Whereas panic attacks, especially with hyperventilation, commonly cause a sense of dizziness that is not actually vertigo, patients with recurrent undiagnosed vertigo can develop panic attacks particularly if the vertigo attacks are reassuringly put down to “. Measurement of blood glucose during an attack, possible with a finger-prick glucometer, is the easiest and most direct way to make the diagnosis of hypoglycaemia, something that is easy to miss in the patient who is not being treated for diabetes. Video-EEG monitoring has proved helpful in the diagnosis of seizures but is not easily available to everyone. A cardiac electrophysiological study is good at picking up the sort of tachyarrhythmias that can cause syncope and is less irksome than an endless sequence of inconclusive indirect investigations. An event monitor which the patient wears for several weeks is more useful, particularly for picking up intermittent heart block, than a 24 hour Holter monitor which is best at disclosing the asymptomatic arrhythmias.
1 2 Cardiac syncope can, particularly in a patient without heart disease, be a difficult diagnosis. (Convulsive syncope is of course more complicated.) Tilt table testing, particularly with lots of invasive instrumentation, is, according to some, too sensitive and insufficiently specific to help much with the diagnosis of vasovagal (now renamed “neurocardiogenic”) syncope. Witness descriptions are not much help in identifying vertigo, but can be essential in identifying seizures and syncope. Obviously patients with aural vertigo should not lose consciousness but it is surprising how few people can give a confident and convincing answer to the simple question: “Did it feel like you were losing your balance or like you were losing consciousness ? Did it feel like you were going to pass out or fall over ?” Patients with vertigo might actually lose consciousness if they have been vomiting a lot, or if they had an otolithic drop attack and a head injury on the way down.
But before we go on to answer that let us consider briefly the diagnosis of other common paroxysmal disorders such as syncope, seizure, hypoglycaemia, and hyperventilation. Now that we are sure that our patient has vertigo the next question to answer is whether the vertigo attacks are spontaneous or positional.
If you don't believe this, then try the following: spin yourself around about 10 times (standing or sitting, it doesn't matter) and then stop and throw your head backwards, quickly.Ĭonvinced? One can be reasonably sure then that the patient who is happy to move around while dizzy does not have vertigo, and that the patient who is dizzy all the time and whose dizziness is not made better by keeping still, either hasn't got vertigo or hasn't got the story right. The third point is that vertigo is always made worse by head movement, just as angina is always made worse by exertion. Even after the vestibular nerve on one side has been surgically severed, the terrible vertigo and nystagmus that follow will always abate within a few days, not because the vestibular nerve has reanastomosed but because profound neurochemical changes have taken place in the brainstem during the process of vestibular compensation. The second point is that vertigo is always temporary. This is true whether the vertigo is induced by being spun around and then suddenly stopped, whether it is induced by having cold water squirted in one ear, whether it is induced by otoconial particles rumbling up and down a semicircular canal duct, or whether it is induced by infarction of one vestibular nucleus. The first point about vertigo is that it is an illusion of rotation and that it is always due to asymmetry of neural activity between the left and right vestibular nuclei. So what is vertigo and what are its mechanisms and clinical characteristics ? The clinician's first job is to sort out whether the dizzy patient is having attacks of vertigo, or attacks of some other paroxysmal symptom. This is of course one of the most common problems encountered in office practice and the one to which Matthews was alluding. (A) The patient who has repeated attacks of vertigo, but is seen while well IS IT VERTIGO ?
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